On the basis of the two specimens we have in hand, and the parallel of the legends for
Maximinus II and
Constantine, I think we can be pretty sure that 1a is a misprint for 1b at
RIC 100.
Unfortunately this issue cannot really be located in the
Gerin catalogue,
nor in
Cohen. It's also hard to find photos of such ordinary, inexpensive late
Roman bronzes; none in
Glasgow or
Mazzini catalogues or
Berk photofile, for instance.
Again I deplore the abysmal underillustration of the early
RIC volumes. If the editors
had undertaken to illustrate one of each major variety, as in
RIC X, yes, the books would be even bulkier and more expensive than they are, but we would be having a lot fewer of these continually recurring discussions of possible errors, diadem forms,
rev. type details, and so on!